For example, there is a behavioral targeting advertising system that displays advertisement recommended for individual persons in accordance with a situation at that time, such as preference of a person that is understood from a purchase history and the like and an air temperature.
In such a system, it is sought to deliver a content real-time. For example, in an advertisement display system in a railroad yard, in a case of displaying advertisement on an automatic vending machine, a customer looks at the panel only for several seconds approximately, so that it turns out to finish a series of process, from input of a user identifier (ID) to display of advertisement, in a few seconds (for example, one second through two seconds).
That is, as a user ID is inputted to an automatic vending machine, process of determining a content to be presented to the user and delivering data of the content to the automatic vending machine for display is finished in a few seconds, thereby enabling the user to look at the content.
However, in a case of delivering data of a content utilizing server resources that are put into one distant data center, there is a problem of delivery delay that is derived from communication delay. In general, the throughput between an automatic vending machine with a display that is located in a downtown and a server that is located at a data center is low (approximately several Mbps) and the size of a video content to be delivered is large (several tens of megabits). For example, when the throughput is 10 Mbps and the content size is 60 megabits, it takes six seconds for delivery while a user is often not willing to wait as much as six seconds.
Regarding such a problem related to the time for display, the following techniques are proposed. That is, a center server obtains an event indicating that a user has come near a display device from an entrance and exit system of a building or the like to deliver a content, taking it as a trigger, for that user to a cache server near the display device in advance. This enables to display the content immediately as the user places an IC card or the like over the display device for reading of the user ID.
However, such techniques have a configuration of sending an event from an entrance and exit system directly to a center server, so that as the number of users increases, events focus on the center server and a decrease in the processing speed of the center server sometimes occurs.
Examples of related art may include Japanese Laid-open Patent Publication No. 2008-252735, Japanese Laid-open Patent Publication No. 2004-310593, Japanese Laid-open Patent Publication No. 2009-100057, and Matoba, K.; Abiru, K.; Ishihara, T., “Service oriented network architecture for scalable M2M and sensor network services”, Intelligence in Next Generation Networks (ICIN), 2011 15th International Conference on 4-7, Oct. 2011, pp. 35-40.